Dr Vladlen Shvedov (left) and Dr Cyril Hnatovsky (right) with a magnified projection of the 'hollow' laser beam (Photo: Stuart Hay, ANU) We're still a far cry from Star Trek's ship-towing and repelling technology, but laser physicists at the Australian National University (ANU) have built a tractor beam that can repel and attract objects. The beam moved spherical glass shells one fifth of a millimeter in diameter across a distance of up to 20 centimeters (7.87 in), which is around 100 times further than previous experiments at this scale, using only a single hollow laser beam that's bright around the edges and dark in its center.